Airplane liquid-spraying device



Oct. 30, 1962 R. E. HYDE AIRPLANE LIQUID-SPRAYING DEVICE 3 Sheets-Sheet1 Filed May 19, 1960 INVENTOR. R/GHARD E. HYDE BY A TTOR/VE Y Oct. 30,1962 Filed May 19, 1960 R. E. HYDE AIRPLANE LIQUID-SPRAYING DEVICE 3Sheets-Sheet 2 INVENTOR. RICHARD E. HYDE WM @N ATTORNEY.

Oct. 30, 1962 R. E. HYDE 3,061,247

AIRPLANE LIQUID-SPRAYING DEVICE Filed May 19, 1960 3 Sheets-Sheet 3INVENTOR. RIG/MRO E. HYDE WM m ATTORNEY United This invention relates toan airplane liquid-spraying device.

When crops are sprayed with liquid insecticides, fungicides, etc.,better and more uniform coverage is obtained and less liquid is wastedwhen the liquid falls on the leaves in an even pattern and in uniformdroplet size, instead of being dispersed unevenly or in a fog or a veryfine mist. The importance of the even pattern is that an exact amount ofthe material is required on each square foot of the area to be treated.The importance of the proper droplets size arises from the facts that(1) large drops tend to touch only part of the plant, and (2) the liquidparticles in a very fine mist tend to evaporate and to be blown away asthey fall, so that some of the liquid never reaches the leaves of thecrop being sprayed and, if the case of convetional airplane sprayers,the distribution is uneven. It takes less liquid to do the same job andthe job is done better when the spray particles are in proper, uniform,droplet size.

The eifectiveness of conventional airplane spraying units has beenimpaired by the air-flow patterns of the air whirled by the propellerand the air passing around the wing, the wheels, the landing gear, andother parts of the plane. The propeller blast moves air from one side ofthe airplane to the other, the direction of flow depending on thedirection of rotation of the propeller, while the air movement at thewing tip is in a vortex from the lower surface of the wing, where theair has greater density, around the wing tips to the upper surface ofthe wing, where the air has less density. Where the two varying airpressures meet, there is a circular air movement like a cyclone along ahorizontal axis. The air movement past the wheels and landing gear isextremely turbulent and uneven, much resembling the varying eddies andcurrents created by protruding rocks in the water currents on aseashore. These air movements have tended to make the spray pattern fromprior-art systems uneven and have tended to break up the sprayparticles, particularly in the the propeller blast area, at the wingtips, and back of the wheels and landing gear, so that the sprayhas beendispersed unevenly and in the form of a very fine mist.

The present invention avoids subjecting the spray droplets to this airdisturbance by issuing the spray droplets at a level below thedisturbance. The spray material is not blown away by the propeller blastor by the air currents created thereby, nor is it affected by the vortexcreatedby the outward movement of air along the wings or the diffusedair currents that pass around the wheels and landing gear. This makes itpossible to reduce the liquid dosage per acre, both because of theresultant evenness of application and because far less is blown away.Moreover, the present invention provides an assembly wherein the sprayboom with its nozzles can be raised and lowered so that they can extenddown low when spraying and at other times can be lifted so as not tointerfere with the landing operation of the plane.

Other objects and advantages of the invention will appear from thefollowing description of a preferred embodiment thereof.

, In thedrawings:

FIG. 1 is a perspective view of an airplane spraying unit embodying theprinciples of the invention. The spray boom is shown in its lowered,spraying'position with theairplane flying. L

FIG. 2 is a perspective view of the spraying apparatus rates Patent iceremoved from the airplane and including the spray boom, the spraynozzles, the spray container tank, and the pump system. Portions of thespray booms are broken in order to conserve space.

FIG. 3 is a view in side elevation and in section of an airplane winghaving the spray boom of the invention and one of the boom supports. Theboom is shown in its raised position where it is close to and generallypar allel to the wing.

FIG. 4 is a view similar to FIG. 3 with the boom shown in its loweredposition.

FIG. 5 is an enlarged View in elevation and in section of the boom andone of its spraying nozzles.

FIG. 6 is a view in front elevation of the boom control apparatusshowing the cockpit controls and the boom on one side of the airplane,with portions broken in order to conserve space. Only one side of theairplane is shown, together with the equalizing valve; the apparatus onthe other side is a symmetrical duplicate.

FIG. 1 shows an airplane 10 with a fuselage 11. The plane 10,illustrated for example only, is a biplane with a lower wing 12 and anupper wing 13. The fuselage 11 has a cockpit 14 for the pilot, and atits-nose it has an engine 15 and a propeller 16. The airplane 10 alsohas a landing gear 17 with wheels 18 and, in conformance withconventional crop-spraying planes, the landing gear 17 is preferably notretractable.

An important problem solved by the present invention relates to the factthat the propeller draft creates strong air currents that tend to breakup liquid droplets. Also, the outward movement of air along the wing 12creates a kind of vortex, and the movement of air past the wheels andlanding gear creates disturbed and uneven air ourrents. The resultingturbulence affects the air adjacent the wing 12, and the propeller 16,and the landing gear 17 for a substantial distance below and above thewing 12, so that when spray nozzles are located closely adjacent to thewing 12, the spray is ejected into the turbulent airstream, where it isbroken up into a fine mist, and into an uneven pattern, therebyimpairing its effectiveness.

In the present invention, the spray unit (see FIG. 2 especially)includes a hollow boom or manifold 20 of substantial length having aseries of nozzles 21. The boom '20 is supported so that it can be raisedparallel to the wing 12 and close to it, as shown in FIGS. 1, 2, and 4.In a normal non-spraying position the nozzles 21 lie .close to the planewing 12, but in spraying position they are below the turbulent areaadjacent the wing; preferably they then lie below the landing gear 17and its wheels 18, as shown in FIG. 1. I

The boom 20 may be supported from the lower surfaced the wing 12 andbelow the fuselage by a series of straight rods 22, which are welded orotherwise secured to the boom 20. Each rod 22 may be joined (See FIGS. 3and 4) by a fastening member 23 to a crank 24 which is. pivoted on afulcrum 25 supported by a stationary bracket 26 carried by and beneaththe wing 12. The crank 24 has-an inclined arm 27 on the opposite side ofthe fulcrum from the rod 22. 'To the arm 27 is pivoted a link 28. Thefastening member 23 includes a shear pin 29 which breaksif the boom 20or rods 22 strike an obstruction, as in forgetfully landing with theboom 20 down; with the shear pin 29 broken, the rods 22 and boom 20swing up out of the way.

A bracket 30 just below the upper surface of the wing 12 supports apivot 31 for a lever 32, which is joined to the link 28 by a pivot 33and has a yoke 34 extending out from the pivot 33 perpendicularly to thearm 32. Thus the lever 32 and link 28 constitute a toggle controlledthrough the yoke 34. A stop member 35 is provided so that in'the' FIG.-3 position thetoggle is substanfrom side to side through the wing 12and is supported by sets of rollers 44 and 45 so that the rod 43 willnot sag. The rod 43 is attached to a piston 46 in a cylinder 47. Therollers 44, 45, and the cylinder 47 may be mounted on the forward edge48 of the wing 12. Thus, when the piston 46 moves to'the left in FIG. 6,it will move the rod 43 to the left and when the piston 46 moves to theright, the rod 43 will likewise move to the right. Movement of the rod43 causes movement of the rod 40 and therefore of the yoke 34 and of thetoggle arms 28 and 32, so that the arms 22 that support the boom 20 areswung up or down, as shown in FIGS. 3 and 4.

Any suitable type of pneumatic or hydraulic actuation may be used toactuate the piston 46. A hydraulic system is shown by way of example.This system incorporates a hand pump 50 with a handle 51 and adirectional control valve 52 with an operating lever 53. Both the handle51 and the lever 53 are preferably in the cockpit 14. A conduit 54connects the pump 50 with the valve 52, while a conduit 55 connects thevalve 52 with a fluid reservoir 56. The valve 52 connects the pumpconduit 54 with one of two conduits 57 and 58 and connects the otherconduit 57 or 58 with the return conduit 55. Thus, when the pilot isflying, he starts off with the spray boom 20 raised just below the wing12. When he Wishes to spray, or shortly before he wishes to, he movesthe handle 53 to actuate the valve 52 so that the conduit 57 is.connected to the pump conduit 54 and the conduit 58 is connected to thereturn conduit 55. He then pumps the handle 51 back and forth to sendhydaulic fluid from 'the hydraulic pump 58 via the conduit 54, valve 52and conduit 57 to an equalizing valve 60, whence it flows by a conduit61 to a port 62 at one end of the cylinder 47,

moving the piston 46 to the left, as shown in FIG. 6. At

the spray boom 20, he moves the control handle 53 to connect the conduit54 to the conduit 58 and then pumps the handle 51 to send fluid throughthe conduit 54, valve 52, conduit 58, equalizing valve 60, conduit 65,and port '64 to the cylinder 47 to move the piston 46 to the right.

A conduit 66 from the equalizing valve 60 leads to the cylinder on theother wing tip.

Each nozzle 21 preferably includes a drip-proof valve 70 (see FIG. Eachnozzle 21 has an inlet 71 connected to the interior passage 72 of themanifold boom 20.

.Adjacent a nozzle outlet 73 is a valve seat 74 against whicha movablevalve member 75 is normally closed. The valve closure member 75 isconnected to a diaphragm 76.. A perforate cover member 77 protects theatmospheric side of the diaphragm 76 and while affording access of airto maintain atmospheric pressure on one side of the diaphragm 76.Atmospheric pressure always tends to move the diaphraga 76 to a positionwhere the valve member 75 rests against its seat 74 and therefore closes-the valve 70. However, when fluid under pressure (that is, when theliquid to be sprayed is being pumped) enters the inlet 71, it flows intoa chamber 78. Its pressure builds up, counteracts the atmosphericpressure on the diaphragm 76, and therefore opens the valve 70 by movingthe closure member 75 away from the seat 74. This arrangement assuresthat liquid will not drip through the nozzles 21 when no spraying isbeing done.

The vast bulk of the spray solution is preferably retained in a tank 80(see FIG. 2) having an outlet tube 81 that leads to a pump 82 whose pumpelement is connected by a shaft 83 to a fan 84. The fan 84 is driven byair when the airplane 10 is in flight, and its rotation operates thepump 82. In other words, the pump 82 is driven by the movement of theplane 10 through the air so that no separate motor is needed and thereis no extra load on the airplane engine 15. From the pump 82 an outlettube 85 leads to a T 86 whence one conduit 87 leads through a valve 88back to the tank 80. Another conduit 90 leads to a valve 91 and fromthere through tubes 92 and 93 to the manifold boom 20.

A lever 94 is preferably mounted by a center pivot 95 on the tube 85.One end of the lever 94 is connected by a link 96 to a crank 97 whichopens and closes the valve 88. The other end of the lever 94 isconnected by a link 98 to a crank arm 99 which opens and shuts the valve91. Thus, the levers and links are arranged to open the valve 91 whenthe valve 88 is closed, and vice versa. Moreover, the link 98 isconnected by an arm 100 to a control member (not shown) in or adjacentthe cockpit 14. When the valve 88 is open, the valve 91 is closed, sothat the pump 82 merely circulates the spray liquid from the bottom ofthe tank 80 around and back into the tank 80 via the conduits 81, 85,and 87. This enables the pump 82 to operate all the time that the fan 84is moving. It also helps to keep the spray solution mixed and, bymaintaining circulation, makes it possible to eliminate parts. When theboom 20 has been lowered to its spraying position, the lever system maybe operated by the arm 100 to close the valve 88 and open the valve 91so that the pump 82 then pumps liquid from the tank 30 into the boom 20.As pressure builds up inside the boom passage 72, the liquid forces openthe valve 70 and the liquid then passes through the nozzles 21 and isdispensed from their outlets 73.

In operation, therefore, the airplane spraying apparatus is normallydisposed with the valve 88 open, the valve 91 closed, and the boom 20 inits upper position. When the plane 10 takes off, everything remains inthis position, but as the plane 10 gathers speed, air drives the fan 84and therefore operates the pump 82 which, at this time, merely mixes theliquid and returns it to the tank 80. The pilot prepares to spray bymoving the directional control lever 53 to its down position and thenpumping the handle 51 until the boom 20 is in its lower position. Whenthe boom 28 is in its lower position, the nozzles 21 are in theirspraying position, and the arm 100 is then used at the beginning of eachrun to open the valve 91 and close the valve 88 and so send liquid underpressure into the boom 20. The pressure of the liquid in the boompassage opens the valve 70 and sends liquid through the nozzle outlets73. There is no need to provide any special venturi action or anythingat the outlets 73, because the sweep of the wind at the end of thenozzles seems to draw the liquid out in the desired form. At the end ofeach run, the lever system is operated by the arm 100 to close the valve91 and open the valve 88. At the end of the spraying operation, the boom20 is moved to its up per position by moving the control handle 53 toits upper position and then pumping the handle 51. The hydraulicpressure holds the boom 20 in its upper position. This is always doneprior to landing the airplane.

To those skilled in the art to which this invention relates, manychanges in construction and widely differing embodiments andapplications of the invention will suggest themselves without departingfrom the spirit and scope of the invention. The disclosures and thedescription herein are purely illustrative and are not intended to be inany sense limiting.

I claim:

1. An airplane spraying unit including in combination a propeller-drivenairplane having a fixed wing, a fuselage, and landing gear; a hollowspray boom of substantial length supported below said fuselage aft ofsaid propeller and below and parallel to said wing, said boom extendingout on bothsides of said fuselage and having a plurality of spraynozzles on each sideof said fuselage; means for pumping spray solutioninto said boom under pressure; and pivotally mounted swinging means forraising and lowering said boom between a non-spraying position closelyadjacent to said wing and a spraying position well below said landinggear, out of the draft of said propeller and out of the turbulence setup by movement of said landing gear through the air, and for holdingsaid boom in either said position.

2. An airplane spraying unit including in combination a propeller-drivenairplane, having a fixed hollow wing, a fuselage, and landing gear; ahollow spray boom extending a substantial distance widthwise of saidairplane having a plurality of nozzles; a plurality of support rodspivotally supported relative to said wing and supporting said boom belowsaid fuselage and below and parallel to said wing; means for pumpingspray solution into said boom under pressure; and means on said wing forsupporting said support rods pivotally; means for swinging said supportrods around an arc of about 90 -for raisin 3 and lowering said boombetween a non-spraying position closely adjacent to said wing and aspraying position well below said landing gear and said wing and out ofthe draft of said propeller and the turbulence set up by movement ofsaid landing gear through the air, and for holding said boom in eithersaid position.

3. An airplane spraying apparatus including in combination an airplanehaving a fixed hollow wing and a fuselage with a cockpit; a hollow boomhaving a series of nozzles thereon located below said fuselage and belowand parallel to said wing; a storage tank for spraying solution; meansfor pumping spray solution into said boom under pressure from saidstorage tank; and means for raising and lowering said boom between anupper nonspraying position closely adjacent the wing and a lowerspraying position well below said wing while holding said boomhorizontally parallel to said wing in both positions, said meanscomprising a pivotally mounted series of rods supporting said boom toswing said boom up and down approximately from a position where saidrods are substantially horizontal to a position where said rods aresubstantially vertical relative to said wing, a hydraulic system havinga hand-operated pump with a control means closely adjacent said cockpit,a directional control valve connected to said pump and also with acontrol means closely adjacent said cockpit, a pair of conduitsconnected to said valve, cylinders having ports at each end connected tosaid conduits and pistons with rods extending out therefrom, inside saidwing, and toggle means inside said Wing connecting said piston-rods tosaid firstnamed rods, so that said pump and valve control the positionof said boom.

4. The apparatus of claim 3 wherein said rods supporting said boom areeach provided with a connection having a pivot pin and a shear pin,normally holding the connection rigid, whereby application upon saidrods or boom of force sufiicient to break said shear pins results inpivoting said boom upwardly away from said force.

References Cited in the file of this patent UNITED STATES PATENTS1,187,981 Doucette June 20, 1916 2,043,262 Oglesby et al June 9, 19362,384,436 Bosscn Sept. 11, 1945 2,772,061 Sellers Nov. 27, -6

FOREIGN PATENTS 134,585 Australia Oct. 10, 1949 OTHER REFERENCESAviation Week, vol. 56 Issue-1, Pub. Date Jan. 7, 1952, p. 15.

